Water-soluble nitrogen-containing heterocyclic compound



Patented Aug. 10, 1943 wli'rsa-sownm mrr moons-commute EROCYCLIOCOMPOUND Oskar Itiester, Dessau, and Gustav Wiimanns, w

Wolfen, Kreis Bitter-fold, G

ermany, assignors,

by mesne assignments, to General Aniline a Film Corporation, New York,N. Y., a corporation of Delaware No Drawing. Application November 14,1939, Se-

iialsNo. 304,820. In Germany Novcmber l5,

' 4 Claims. (01. 260-290) This invention relates to water-solublenitrogen-containing heterocyclic compounds.

The non-quatemary nitrogen-containing heterocyclic bases are for themost part very little soluble in water and obtain considerable watersolubility only when their nitrogen atom is ren- .dered quaternary byaddition of alkyl acid radicals. The cyanine dyes obtained "in the usualmanner from such quaternary salts by-condensation possess only smallsolubility in water in spite of the presence of the quaternary nitrogenin the form of the iodides as they are obtained by synthesis. into moresoluble salts, for instance chlorides or nitrates, and even this measureis often not sumcient for highly molecular dyestuffs. It is thereforenecessary to employ organic solvents in order to obtain a clear solutionof the dyestufis. When pouring such solutions into aqueous gelatinsolution for instance for the production of filters there exists alwaysthe danger that the dye-.

stlifls separates before dilution in the great amount of gelatinsolution effects dissolution of the dye therein. Th water solubility ofthe cyanines has paramount importance in the production of sensitizedemulsions for films, plates and paper especially for the purpose ofreproduction and color photography. In these fields there are not onlyrequirements as regards intensity and f astness of the sensitization andas regards gradation but great stressis laid on the require- Very oftenthey must be transformed ment, that the finished emulsion layer is notcolored by the sensitizers. The hitherto known basic and acidsensitizing dyes fulfill these requirements only imperfectly. Thefinished emulsion layers nearly always show a more or less noticeableresidual discoloration which may look yellow, reddish or blueishaccording to the wave lengths, for which the emulsion is sensitized.This discoloration is caused by the lack in water solubility of thehitherto employed cyanine dyes which causes the dye to be not entirelywashed out of the gelatin layer by the treatment baths.

The acid dyes of the eosin-class are easily soluble in water, but theypossess to a certain degree-substantive properties towards gelatin sothat a complete washing out does not occur in this case.

stance piperidine.

amino-group. This object is achieved by reacting a nitrogen-containingheterocyclic base containing a benzene ring fused onto the heteroring,the benzene ring carrying an amino-group, such as for instance2-methyl-6-amido-benzthiazole with an w-halogen aliphatic acyl halide ofaltogether no more than 3 carbon atoms, for instance chloroacetylchloride whereby a halogencontaining amide is produced. The temperaturesused for this condensation depend upon the reactivity of the reactants.If the reactivity is great the reaction mass must be cooled below 0 C.if not it must be heated. As w-halogen acyl halide especiallychloroacetylchloride, p-chloropropionic acid chloride and the'like maybe employed. The intermediate product is then reacted by heating with asecondary or tertiary aliphatic,

aromatic or heterocyclic amine to yield an easily water-solublecompound. Tertiary aliphatic amines such. as forinstance triethylamine,dimethylhydroxyethylamine etc. or also cyclic amines such as forinstance pyridine, isoquinoline and their substitution-products orheterocyclic amines such as for instance thiazoline, thiazole etc. aresuitable for the purpose. Furthermore secondary amines may be used inwhich the nitrogen atom is a member of a ring such as for in- Thereaction may be made more clear following formula:

(CH ),.-halogen NR. 0 X

HsC-C amine by the cyanine-dyes of any desired constitution(carbocyanines, pseudocyanines, isocyanines, symmetricalmonomethinecyanines, styryl dyes, long chain polymethinecyanines,rhodacyanines, merocyanines, etc.). The cyanine dyes thus obtainedpossess high water solubility.

Example 1 grams of 2-methyl-6-amidobenzthiazole are dissolved in 150 cc.of pyridine and 34 grams of chloroacetylchloride in cc. benzene areslowly added at minus 10 C. After stirring for an hour 100 grams of iceare added and the colorless crystals ofw-chloroacetamido-2-methylbenzthiazole filtered and recrystallized frommethanol. Melting point 1'74 to 175 C.

This product can be reacted with pyridine for instance in the followingmanner: 10 grams of the product are heated with 20 cc. of pyridine forhalf an hour to C. and recrystallized after cooling from propanol.Melting point: 239 C. They can also be crystallized from methanol. Themelting point is then 91 C. The product contains methanol in thecrystals. The resulting product has the following formula:

N 1 ci- It can be reacted in known manner with diethylsulfate and canthen be converted in pyridine with ortho-formic acid ester by .heatingfor 3 hours to 110 C. to yield a red-violet dye of the followingconstitution:

Example 2 The reaction product of 2-methyl-6-amidobenzthiazole withchloroacetylchloride named in Example 1 is heated to C. for half an hourwith double its weight of isoquinoline and the resulting productrecrystallized from propanol.

Melting point 243 C. The product has the fol- 6 lowing constitution:

Example 3 5 grams of the 6-(o-chloroacetylamido) -2- methylbenzthiazolenamed in Example 1 are heated to 100 C. for'5 minutes with 5 gramspiperidine in the oil bath, when reaction sets in and the whole batchsolidifies. The product is recrystallized from propanol. It has thefollowing formula:

Ht-H:

Example 4 From Z-methylbenzoxazol the 6-nitro-2-methyl-benzoxazole isprepared by nitrating in concentrated sulfuric acid and the latterreacted with stannous chloride in hydrochloric acid to yield6-amido-benzoxazo1e of a melting point of C. The latter can be convertedwith chloroacetylchloride in the manner described in Example 1 into acompound of the following constitution:

Further treatment follows the prescription given in Example 1.

Example 5 I S-amidoquinaldine is reacted with chloroacetylchloride asdescribed in Example 1. The following compound having a melting point of189 to 190 C.isproduced: I

N/CHI It is boiled for half an hour i 5 times its weight of pyridine at110 C. and recrystallized after cooling with an addition of propanol.The com- S NH.C 0

' H, N l L N pound obtained has 'a melting point of 137 to 139 C. andhas the following constitution:

{C Hi 01' Example 6 The reaction product of 2-methyl-6-aminobenzthiazolewith chloroacetylchloride named in 0 Example 1 i heated to 90" c. withthe same amount of dimethylhydroxyethylamine and the same amount ofpropanol. A reaction occurs during which a part of the propanolevaporates. The double amount of propanol is added and the 75 reactionmass left to crystallize over night. The

crystals obtained are washed with propanol and finally with dry etherand dried on clay. The following compound results in good yield:

Melting point 168 to 170 C.

Example 7 v 50 grams of 2-methyl-6-amlnobenzthiazole are dissolved in150 grams of hot pyridine and after cooling to minus (3., there areslowly added 36 grams of fi-chloropropionic acid chloride in 100 cc. dryether while stirring. After an hour a reaction product having theconstitution as follows is precipitatedby addition or a great amount ofice:

NH--C O-CHz-CHzCl Melting point 118 to 119 C. from propanol.

8 grams of this productare heated in 2 cc. of pyridine in an oil bath to110 C. for 3 quarters of an hour. 10 cc. of butanol are added and thereaction product precipitated with about 40 cc. of dry ether. It has thefollowing constitution:

HaC-C precipitated as the sulfide. The solution is made alkaline, withcaustic soda and extracted with benzene. After evaporation2-methylmercapto- 5-aminobenzthiazole crystallizes as a pale-yellowpowder. Melting point 96 C.

6.5 grams of this thiazole are dissolved in 30 cc. of pyridine and 4grams or chloroacetylchloride added at minus 5 C. The mixture is pouredon- Melting point 265 C., decomposition from 250 C. upwards. It iseasily soluble in th lower alcohols and flows with water.

Example 8 grams of 2-methyl-N-phenyl-5-amidobenzimidazole are dissolvedin 150 cc. of pyridine and 22 grams of chloroacetylchloride in 100 cc.of ether are added dro by drop at minus 10 C. The mixture is stirred foranother hour and then diluted with 200 cc. of ice, finally 22 grams ofdry soda are added and cooled to minus 5 C. The separated product isfiltered and recrystallized from propanol. Melting point 298 C. aftersintering at 158 C. The product has the follow- J ing constitution:

10 grams of this w-chloroacetaminobenzimidazole are heated to the boilin 10 cc. of pyridine for half an hour. The product is fluid for a shortwhile and then again solidification occurs. It is recrystallized frommethanol and dried over night at 60 C. Melting point 206 to 207 C.Insoluble in ether and benzene, very easily soluble in water.

GuHs

HaC-C Example 9 18 grams of 2-methyl-mercaptobenzthiazole are dissolvedin 40 cc. of concentrated sulfuric to cc. of ice, filtered andcrystallized from propanol. Melting point 146 to 148 C.

S Cl-GHr-C O-NH C-SCHI By warming with pyridine or another amine thisproduct which is nearly insoluble in water yields an .ammonium saltwhich is easily soluble in water. l

i We claim:

l. A. compound having the following general formula:

wherein X is amember selected from the group consisting of S, 0, Se,

CH; CH:

N-alkyl, N-aryl, N-aralkyl, CH=CH-; R is a member selected from thegroup consisting of H or alkyl; 1:. is a whole number smaller than 3;

Y is a member selected from the class consisting of I wherein A isselected from the group consisting of alkyl and aryl and NEB is aradicle of a heterocyclic amine; wherein the acid amide radical 'isattached to any of the four positions of the benzene ring.

2. A compound of the following general formula:

B HaC-C 4 2,aaa,497

3. A. compound of the following general tor- 4. A compound of thefollowing general 101'- muh: mula:

5 @-0Hr-oo-NH 11/ h-cm-oo-mz 1 /ccn. 01-

El {1\H C-CH: N/

. m osxm mm.

4 GUSTAV WILMANNS.

